


undertow

by fatal_drum, TwoDrunkenCelestials



Series: we, too, have teeth [2]
Category: The Magnus Archives (Podcast)
Genre: Biting, Chasing, Claiming, Come Marking, M/M, Oral Sex, Selkie Jonathan Sims, Selkie Martin Blackwood, Trans Jonathan Sims, Trans Martin Blackwood, Vaginal Sex, magical selkie dick powers, mutual possessiveness, references to past abuse/noncon
Language: English
Status: Completed
Published: 2021-02-11
Updated: 2021-02-11
Packaged: 2021-03-18 06:26:43
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,941
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29363955
Author URL: https://archiveofourown.org/users/fatal_drum/pseuds/fatal_drum, https://archiveofourown.org/users/TwoDrunkenCelestials/pseuds/TwoDrunkenCelestials
Summary: Years later, Jon and Martin re-stake their claim on one another, with no witnesses save the moon and the sea.
Relationships: Jonathan Sims/Martin Blackwood
Series: we, too, have teeth [2]
Series URL: https://archiveofourown.org/series/2155779
Comments: 8
Kudos: 90





	undertow

**Author's Note:**

> For our readers, who have been suffering through so much selkie pain: a glimpse into a happier future. 
> 
> Many thanks to cuttooth for their screaming, betaing, and cheerleading. <3
> 
> Words used for Jon and Martin’s anatomy: breasts, cunt, cock

It’s a quiet night in their little cottage. Martin has just finished tucking the pups into bed. They barely made it through their bedtime stories before they nodded off. His heart swells with affection for his small family. His mate is outside on the veranda, waiting with two cups of chamomile tea. 

“Which story did you tell them?” Jon asks once he’s shut the door. He’s wearing one of Martin’s t-shirts. It’s so loose that it hangs off of one shoulder, and it’s just long enough to skim his thighs. The sight sparks something warm and possessive in Martin, a feeling he can thoroughly indulge in these days. He places his hand on the small of Jon’s back. Jon leans against him, head on Martin’s shoulder. 

Martin smiles fondly. “Meri’s into dinosaurs these days, so we got the tale of the brave little plesiosaur.” 

“Did he growl and pretend to hunt his sister?” Jon makes a clawing gesture, snickering. 

“Oh, yes,” Martin says, laughing. “But she was a much larger liopleurodon, so she chased him off.”

Jon nods sagely. “A very wise strategy.”

They stare out over the water in companionable silence. The moon is waxing, fat and bright, reflecting on the dark waves. The song of the sea is soft and lulling, a mélange of the surf, shorebirds, and the cool breeze around them. Their home is paradise for a family of free selkies, able to answer the call of the tides. 

Martin is broken from his reverie when Jon nuzzles at his neck. 

“You know,” Jon whispers. The warm caress of his breath makes Martin shiver. “We’re all alone right now.” 

Martin feels the scrape of teeth against his throat, and bites down a whimper. 

“We are,” he says, fighting to sound unaffected. Jon apparently takes exception to that, because the next thing he does is nip at Martin’s throat. 

“What are you going to do about that?” Jon asks, soft and teasing. 

Martin swallows hard, arousal already coiling in his belly. 

“What would you  _ like  _ me to do?” he asks with a coy smile, tilting his head back to expose more of his neck. 

Jon’s teeth close around the tender flesh, and Martin moans out loud, gripping the rail of the balcony for support. 

“Catch me,” Jon whispers. Before Martin can respond, Jon pulls back, vaulting over the railing and onto the sand. He grins over his shoulder, toothy and a bit wild. 

Martin can’t turn down a challenge like that. Secure in the knowledge that their family is safe, he follows Jon over the balcony rail, landing in the soft sand. Jon peels off his shirt as he runs, tossing it over his head. It lands on a tuft of grass off the main path. Martin has a feeling he knows where Jon is going. 

“You’ll have to run faster than that if you want to catch me!” Jon says, shooting a smug look over his shoulder. 

“I’m getting old!” Martin laughs, doing his best to match Jon’s pace. He follows Jon past a bend in the path where two trees grow. His racing pulse, the feeling of his blood pumping through his muscles as he runs, only adds to his excitement. Chasing Jon over the cool sand makes him feel incredibly  _ alive.  _

He knows they’re close when Jon sprints into the water. The waves are only waist-high, but they’re enough to slow him down. Martin almost catches him, his arms closing on empty water, but Jon evades him at the last second. They’d both be faster with their pelts, but those are safely hidden in the house. Jon laughs as he climbs onto the little rocky outcropping that’s become their favorite spot for resting and sunning themselves. They can see their house in the distance behind them. 

“You’ve got me cornered, Mr. Blackwood,” Jon teases, reclining on his elbows. The position shows off his lean body, his small but mouth-watering chest, and the trail of wispy dark hair that leads down his belly and between his thighs. He still has the scars of their captivity—they both do—but they're faded, and covered with clean marks from Martin's teeth. Jon has done the same for him. The only exception is Jon's tattoo, which they'd had covered with a larger piece: two seals curled around each other, wreathed in seaweed and shells.

“So I do, Mr. Blackwood,” Martin says, smiling as his eyes trail down Jon’s body. 

Martin lies next to his mate, leaning over to claim his mouth in a soft, tender kiss. Jon shudders, pressing himself against Martin’s front. Slowly, Martin deepens the kiss, licking into Jon’s mouth. Jon is the first to introduce a hint of teeth, nibbling on Martin’s lower lip. 

“We have a blanket,” Martin says gently. They’d been sunbathing the day before and had neglected to bring it back inside. 

“It’s too far away,” Jon complains. 

“Just a moment,” Martin says, kissing his cheek. He grabs the waterproof case and unzips it, rolling out the soft blanket for Jon to lie on. Jon promptly grabs Martin’s shoulders, pulling him down onto his body. 

“I love you,” Jon says, kissing him again. “My mate, my starlight. My Martin.” 

Martin’s heart feels so full it could burst. “I love you, too.” 

Martin nuzzles Jon’s neck, right over the mating mark. Jon purrs deep in his chest, baring his throat, and Martin bites down gently. 

“H-harder!” Jon moans, wrapping his legs around his waist and dragging him closer. “Please, love.” 

Martin growls, biting down more firmly, until he tastes blood. The scent of blood mixes with the salt of the sea around them, making Martin purr in satisfaction. Everything is as it should be. He can feel Jon burying his face in his hair, breathing in his scent and taking comfort in it. 

He works his way down to Jon’s collar bones, licking and nibbling his way down, until he reaches his breasts. They’re softer than they used to be, after nursing their second child. He cups them, enjoying the small weight of them in his hands, before sucking a nipple into his mouth. Jon gasps, hands tightening on Martin’s shoulders. 

“You’re so beautiful,” Martin murmurs, biting down gently. Jon moans, nails digging into Martin’s skin. “I love touching you. Tasting you.” 

“Yes, Martin, please…” 

Martin shifts his attention to the other side, licking and sucking the firm flesh until Jon growls and pushes his head down. 

“More…” Jon demands, thrusting up against Martin’s body. Martin pins him by the hips. It’s only in the last year or so that they’ve been able to do these things, to pin and bind each other without feeling ghosts of their past. It feels good to trust his mate, and to be trusted by him in turn. 

He can’t deny his mate for long, though. He kisses and licks his way down Jon’s belly, biting down at the jut of his hip. The scent of Jon’s arousal makes his mouth water, his cunt clenching around nothing. He nuzzles his way into the nest of curls, opening his mouth to give Jon a delicate lick. Jon bucks against his mouth, and Martin sucks his cock between his lips, savoring the salty musk of him. Jon’s nails scrape up the back of his neck, and Martin moans around his cock.

“Your mouth feels so good,” Jon praises, running rough fingers through Martin's hair. 

Martin groans around Jon’s cock. He can feel Jon growing larger in his mouth, and he thinks he knows where this is going. It’s a trick they’ve perfected over the last few years, shifting their anatomy to suit their needs. Gradually Jon fills his mouth, the weight of him warm and comforting on his tongue. 

“Do you want me inside of you?” Jon asks, his voice husky with desire. 

Martin lets out an involuntary whine. He pulls off, dropping a fond kiss on the tip of Jon’s cock. “Fuck, yes, please, Jon…”

“Ride me,” Jon says challengingly, and that’s all Martin needs to climb to his knees and straddle Jon’s hips. 

Martin rubs against him, spreading slick over his cock, and they both moan. 

“Like this?” Martin asks teasingly, moving his hips in slow circles. 

Jon reaches down to brush his fingers against Martin’s entrance, just short of pushing in. Martin whines high in his throat. Jon’s thumb brushes against Martin’s cock, making him gasp. 

“Maybe,” Jon says coyly. “Or you could sink down onto my cock, and let me watch your cunt stretch around me.” 

The words are  _ devastatingly  _ filthy. Martin can’t stop the little whimper that leaves his throat. 

Jon looks straight into his eyes, trapping him with his gaze. “Don’t you want me to fill you up? To come inside you, so everyone knows you’re  _ mine?”  _

Martin’s so wet he knows he must be dripping. He gives up on any restraint, positioning himself so he can sink down on Jon’s thick cock. He can feel Jon opening him up, sliding into him like he belongs inside him. They both moan as he bottoms out, shifting his hips as he adjusts to Jon’s girth. 

Jon’s pupils are blown, his smile full of teeth and anticipation. Martin leans forward to pin his wrists, grinning down at him. 

_ “Mine,” _ Martin growls, rolling his hips. Jon gasps, hips surging up to meet him. Martin rides him smoothly, their bodies moving against each other like the tide, a steady ebb and flow that leaves Martin breathless. 

Jon’s eyes are wide and adoring as he begs, “Please, love, let me touch you—”

Martin releases his wrists, and Jon grabs his hips, pulling him down hard onto his cock. Martin groans, grinding against Jon’s body. Their pace becomes more urgent, their thrusts deeper and less controlled. Jon’s hand slips between them, rubbing Martin’s cock in firm circles, making him clench tight around him. His eyes never leave Martin’s face, drinking in his reactions with each touch. 

No one has ever wanted Martin so completely, so consumingly. Before, Martin was a toy, a possession. Something to be coveted but not cared for. Now he knows he is Jon’s everything, just as Jon is his. Aside from their family, nothing else matters. No one can ever break them apart. 

Martin can feel the pleasure building, coiling in his belly and between his thighs. He can feel the pull like undertow, slowly dragging him under. “J-jon—” he cries, head thrown back in ecstasy. 

_ “Yes,”  _ Jon growls, his voice barely human. “Come for me.”

His fingers find just the right spot, and Martin comes with a wail, gushing and spasming around Jon’s cock. Jon eases him through it, milking every last tremor from his body. Martin collapses against him, burying his face in his shoulder. Martin sighs in satisfaction. 

“I need—” Jon pants, rolling them both onto their sides. He pulls out, jerking himself with short, harsh strokes. His eyes stay fixed on Martin’s. Moments later, he comes in spurts, covering the remnants of Martin’s brand, long since reclaimed with Jon’s teeth and his kisses. Afterwards he rubs his come into his skin, pushing some of it into Martin’s dripping cunt. 

_ “Mine,”  _ he proclaims, kissing Martin gently. 

“Mine,” Martin echoes. 

They lie with their limbs entangled, pressing kisses to each other’s faces, as close as they can get without sharing one skin. Soon they will need to return, but for now, they can rest, entwined as they were meant to be. The waxing moon shines a blessing on their union, illuminating the planes and curves of their bodies. The lights of their cottage shine in the distance, a beacon to guide their way home.


End file.
